In general, many systems or apparatuses need to be used for radiation treatment in hospitals. Types of these systems and apparatuses include an electronic medical record (EMR) system, an order communication system (OCS), a picture archiving and communication system (PACS), a radiation treatment planning (RTP) system, and a radiation treatment device, for example, a linear accelerator (LINAC).
OCS is a system that transmits a database (DB) for storing various medical information and patient examination data and prescriptions that are made after doctors have diagnosed patients, to corresponding examination departments over a communication network.
The EMR system is a system that is configured to store and search for EMR.
PACS is a system that stores and transmits images captured by at least one medical imaging apparatus including a computed tomography (CT) device, a magnetic resonance imaging (MRI) device, a positron emission tomography (PET) device, a CT simulator, and computed radiography (CR), in a computer file format. PACS is equipment that has been mostly introduced in medium-sized hospitals.
The RTP system is a system that systematically establishes (draws up) a patient's radiation treatment plan, i.e., drawing-up of radiation treatment plan information, calculating and checking a radiation dose. By using the RTP system, a user selects an optimum image from among images of the patient's body in areas where cancer is located, which are acquired by the CT device or the MRI device; or a doctor examines the patient's medical photos, digitizes and images them and then performs basic image processing, sets reference coordinates of the acquired images and performs contouring of each of the areas thereby calculating a direction of beams and a radiation dose according to the sizes of the areas in which cancer has occurred.
A basic principle of radiation treatment is to target the treatment to minimize the occurrence of acute and chronic radiation reactions that may occur in normal tissues, reduce complications, or prevent causing a secondary tumor while performing cancer treatment. To this end, an appropriate radiation treatment plan needs to be established.
The radiation treatment device is a device that actually performs radiation treatment on the patient based on the radiation treatment plan that is drawn-up using the RTP system.
Cancer treatment methods in the area of radiation oncology have developed over the years and have become diverse. Thus, new treatment devices and applications of various treatment methods have been developed.
A procedure of performing radiation treatment on the patient in a radiation oncology department will be described below. First, the patient's medical images are acquired using a medical imaging device so as to acquire information regarding the patient's cancer. Thereafter, the radiation treatment plan is established based on the patient's medical images using the RTP system. Next, radiation treatment is performed using the radiation treatment device based on the radiation treatment plan that is established using the RTP system.
In this case, radiation treatment devices, such as LINAC, brachytherapy, cyberknife, and tomotherapy, have been developed and used. These radiation treatment devices have been properly selected according to the patient's cancer state or treatment area.
In a conventional radiation treatment system, before radiation treatment is performed, radioactive rays have been used so as to check whether the patient position during present radiation treatment is same as his or her position during previous radiation treatment, for example, during initial radiation treatment or during simulation treatment.
For example, since, in tomotherapy, treatment beams are radiated while diagnosis radiographs are taken, irradiation for checking the patient's initial position while irradiation is performed in a double manner, may cause problems in the treatment plan.
Also, even though a difference between the patient's original position and the patient's current position is known, when images are matched or fused so that the patient can be moved or a diagnosis couch is manually moved, the patient may move, and treatment may be delayed, which causes inconvenience during the radiation treatment.
Furthermore, in the conventional radiation treatment system, when the patient's movement occurs during radiation treatment, the treatment beams are radiated onto a position or region different from a region of interest (ROI) of radiation treatment. Thus, cancer cells in the ROI are not treated but normal tissues are exposed to radiation and may be negatively affected.
Thus, it is essential to perform radiation treatment by continuously monitoring the patient's movement.
Korean Patent Registration No. 10-1212792 that is a prior art for solving these problems discloses a patient arrangement system for a radiation therapy system, whereby control signals for moving at least one of a movable patient positioner and a radiation nozzle are generated and position information that indicate current spatial positions of one or more selected from the patient positioner, the radiation nozzle, and fixed reference objects are obtained from a plurality of external measurement devices.
However, the prior art has problems that, since the plurality of external measurement devices are disposed at several angles and the patient position is checked and corrected using image analysis and position signals from each of the plurality of external measurement devices, the structure of the patient arrangement system is complicated and the amount of calculation is increased.
Korean Patent Publication No. 2008-0039916 that is a prior art for monitoring a patient position or movement in a conventional radiation treatment system, discloses a system and method of performing radiation treatment in a moving ROI, whereby the patient is monitored while radiation treatment is performed and a treatment plan is changed in consideration of breathing patterns determined in a monitoring operation.
However, in the prior art, since all of treatment plans need to be set based on the patient's breathing patterns, when the patient's breathing patterns are different from set breathing patterns, it is difficult to change the treatment plans. In addition, since only the breathing patterns are considered, if the patient moves while on the diagnosis couch in a state in which the same breathing patterns are maintained, treatment beams may not be radiated onto the ROI but may be radiated onto a different region such that a normal part may be exposed to the treatment beams.
Thus, there is an increasing need for a method of automatically controlling a patient position, whereby the patient position can be automatically controlled with a simple structure while reducing a radiation dose exposed to the patient and the patient position is monitored so that, even when the patient moves, a normal part can be prevented from being exposed to treatment beams.